Messages in this thread | | | From | "Madhusudhan" <> | Subject | RE: [PATCH v3] OMAP: Fix for bus width which improves SD card's peformance. | Date | Tue, 6 Apr 2010 11:16:01 -0500 |
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> -----Original Message----- > From: Felipe Balbi [mailto:me@felipebalbi.com] > Sent: Tuesday, April 06, 2010 12:01 AM > To: Madhusudhan > Cc: me@felipebalbi.com; 'kishore kadiyala'; 'Vimal Singh'; > tony@atomide.com; svenkatr@ti.com; linux-omap@vger.kernel.org; linux- > kernel@vger.kernel.org; jarkko.lavinen@nokia.com > Subject: Re: [PATCH v3] OMAP: Fix for bus width which improves SD card's > peformance. > > Hi, > > On Mon, Apr 05, 2010 at 12:19:29PM -0500, Madhusudhan wrote: > > Since the first if command already checks for the 8-bit the second check > > like >= 4 is definitely not readable in my opinion. > > how come ??? > > > Functionally do you see anything wrong with this patch?? > > functionally no, but (hypothetical situation) and if on > omap4/5/6/whatever, omap controller supports a bigger bus width then > you'll have to add a line like: > > + if (mmc_slot(host).wires == 16) > + mmc->caps |= (MMC_CAP_16_BIT_DATA | MMC_CAP_8_BIT_DATA | > + MMC_CAP_4_BIT_DATA); > - if (mmc_slot(host).wires == 8) > + else if (mmc_slot(host).wires == 8) > > do you see the problem ?? In my opinion it doesn't scale well. >
The point we should note here is that MMC spec supports a max bus width of 8-bit. So anything beyond 8-bit is not in the picture as of today.
But, my bad on miss interpreting the snippet Felipe sent earlier.
if (mmc_slot(host).wires >= 8) mmc->caps |= MMC_CAP_8_BIT_DATA; if (mmc_slot(host).wires >= 4) mmc->caps |= MMC_CAP_4_BIT_DATA;
I missed the fact that you removed the setting of 4-bit from the first check.
I am okay with the above snippet as it is a trivial change that we are trying to patch here which fixes an important issue.
Regards, Madhu > -- > balbi
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